In electronics, leakage may refer to an undesired loss of energy or to an undesired current flow. For example, a current of a high voltage section, e.g. power electronics or 400V battery pack of an EV (Electrical Vehicle), leaks out of the (high voltage) circuit part in an unintended way and flows into another circuit part which should be electrically isolated from the first circuit part, e.g. by a galvanic separation. The second circuit part may be a low voltage section (e.g. 12V, 5V, 3.3V or less) comprising a sensor, e.g. a current sensor for sensing the current flowing within the (high voltage) circuit part. Typically the low voltage circuit part includes the human interface, wherein the galvanic separation should ensure that any current cannot flow from the high voltage section to the low voltage section so that the low voltage section does not pose a danger to the user. Especially in case of EVs, the requirements regarding such galvanic separations are high. These requirements are specified in standard specification for functional safety, as given by actual standards like ISO 26262 (as relevant in the safety-critical automotive domain).
Designs fulfilling this standards will also require certain diagnostic capabilities to detect a possible dangerous break-through cases before these happen. This is required to warn the user in advance and allows an in-time maintenance cycle of critical or pre-damaged parts.
Currently, the requirements regarding the galvanic separation of the high voltage section and the low voltage section is achieved by increasing the isolation distance between the two sections, special diagnosis is omitted. However, beside a general trend to better diagnosed systems, there is a move towards reducing such isolation distances due to miniaturization and cost reduction. This may lead to an increased likelihood of electrical leakage due to effects like migration of electrons caused by delamination or moisture. Therefore, there is the need for an improved approach and by taking a possibility of diagnosis into account.